The application relates to a process for the preparation of synthesis gas by the partial combustion of a finely divided carbon-containing fuel with an oxygen-containing gas in a reactor. The application also relates to a reactor suitable for carrying out the process.
The synthesis gas thus prepared mainly consists of carbon monoxide and hydrogen and contains in addition, inter alia, minor quantities of carbon dioxide, water vapor and methane. If the partial combustion is not carried out with pure oxygen but with air, the product of course also contains much nitrogen.
By carbon-containing fuel is preferably meant coal and other solid fuels, such as brown coal, peat, lignite, waste wood, etc., but liquid fuels such as oil, optionally derived from tar sand, are also suitable.
The reactor is preferably mainly cylindrical, but oval or rectangular and similar reactors are also suitable.
Such a process and reactor are generally known. The finely divided carbon-containing fuel and the oxygen-containing gas have hitherto mostly been supplied together to the reactor by means of burners. The fuel and the oxygen are intermixed in or just upstream of the burner and interreact in the reactor.
The burners are very important parts of a gasification plant. An incorrect design or faulty setting of a burner causes poor mixing and combustion with, as a least serious effect, a lower yield of synthesis gas and/or increased soot formation. In a more serious effect, a flashback of the flame may occur in the burner or in the fuel feed line, or the flame may become too large and cause the reactor wall opposite the burner to become overheated. The solid, hard impurities in the fuel, such as sand grains, cause wear of the burners, owing to which the flame pattern and the gasification efficiency are adversely affected.
This critical role of the burners led to much research work involving many improvements in the details of their design. But, the above-mentioned problems are inherent in the concept of burners and may therefore always occur, although certain burners may tend to develop them rather earlier than others.
According to the present invention, the use of burners is avoided and consequently one is freed from such problems. This is preferably accomplished by supplying the oxygen-containing gas axially to one end of the reactor and feeding the fuel into the reactor downstream of the gas inlet at an angle of 90.degree. (.+-.20.degree.) to the reactor axis from a centrifugal pump located inside the reactor.